Added a ManyToManyField(db_constraint=False) option, this allows not creating constraints on the intermediary models.
This commit is contained in:
Alex Gaynor
parent
4cccb85e29
commit
bbbd698c7a
|
|
@ -955,7 +955,9 @@ class OneToOneRel(ManyToOneRel):
|
|||
|
||||
class ManyToManyRel(object):
|
||||
def __init__(self, to, related_name=None, limit_choices_to=None,
|
||||
symmetrical=True, through=None):
|
||||
symmetrical=True, through=None, db_constraint=True):
|
||||
if through and not db_constraint:
|
||||
raise ValueError("Can't supply a through model and db_constraint=False")
|
||||
self.to = to
|
||||
self.related_name = related_name
|
||||
if limit_choices_to is None:
|
||||
|
|
@ -964,6 +966,7 @@ class ManyToManyRel(object):
|
|||
self.symmetrical = symmetrical
|
||||
self.multiple = True
|
||||
self.through = through
|
||||
self.db_constraint = db_constraint
|
||||
|
||||
def is_hidden(self):
|
||||
"Should the related object be hidden?"
|
||||
|
|
@ -1196,15 +1199,15 @@ def create_many_to_many_intermediary_model(field, klass):
|
|||
return type(name, (models.Model,), {
|
||||
'Meta': meta,
|
||||
'__module__': klass.__module__,
|
||||
from_: models.ForeignKey(klass, related_name='%s+' % name, db_tablespace=field.db_tablespace),
|
||||
to: models.ForeignKey(to_model, related_name='%s+' % name, db_tablespace=field.db_tablespace)
|
||||
from_: models.ForeignKey(klass, related_name='%s+' % name, db_tablespace=field.db_tablespace, db_constraint=field.rel.db_constraint),
|
||||
to: models.ForeignKey(to_model, related_name='%s+' % name, db_tablespace=field.db_tablespace, db_constraint=field.rel.db_constraint)
|
||||
})
|
||||
|
||||
|
||||
class ManyToManyField(RelatedField, Field):
|
||||
description = _("Many-to-many relationship")
|
||||
|
||||
def __init__(self, to, **kwargs):
|
||||
def __init__(self, to, db_constraint=True, **kwargs):
|
||||
try:
|
||||
assert not to._meta.abstract, "%s cannot define a relation with abstract class %s" % (self.__class__.__name__, to._meta.object_name)
|
||||
except AttributeError: # to._meta doesn't exist, so it must be RECURSIVE_RELATIONSHIP_CONSTANT
|
||||
|
|
@ -1219,13 +1222,15 @@ class ManyToManyField(RelatedField, Field):
|
|||
related_name=kwargs.pop('related_name', None),
|
||||
limit_choices_to=kwargs.pop('limit_choices_to', None),
|
||||
symmetrical=kwargs.pop('symmetrical', to == RECURSIVE_RELATIONSHIP_CONSTANT),
|
||||
through=kwargs.pop('through', None))
|
||||
through=kwargs.pop('through', None),
|
||||
db_constraint=db_constraint,
|
||||
)
|
||||
|
||||
self.db_table = kwargs.pop('db_table', None)
|
||||
if kwargs['rel'].through is not None:
|
||||
assert self.db_table is None, "Cannot specify a db_table if an intermediary model is used."
|
||||
|
||||
Field.__init__(self, **kwargs)
|
||||
super(ManyToManyField, self).__init__(**kwargs)
|
||||
|
||||
msg = _('Hold down "Control", or "Command" on a Mac, to select more than one.')
|
||||
self.help_text = string_concat(self.help_text, ' ', msg)
|
||||
|
|
|
|||
|
|
@ -1227,6 +1227,20 @@ that control how the relationship functions.
|
|||
the table for the model defining the relationship and the name of the field
|
||||
itself.
|
||||
|
||||
.. attribute:: ManyToManyField.db_constraint
|
||||
|
||||
Controls whether or not constraints should be created in the database for
|
||||
the foreign keys in the intermediary table. The default is ``True``, and
|
||||
that's almost certainly what you want; setting this to ``False`` can be
|
||||
very bad for data integrity. That said, here are some scenarios where you
|
||||
might want to do this:
|
||||
|
||||
* You have legacy data that is not valid.
|
||||
* You're sharding your database.
|
||||
|
||||
It is an error to pass both ``db_constraint`` and ``through``.
|
||||
|
||||
|
||||
.. _ref-onetoone:
|
||||
|
||||
``OneToOneField``
|
||||
|
|
|
|||
|
|
@ -113,8 +113,8 @@ Minor features
|
|||
* The ``MemcachedCache`` cache backend now uses the latest :mod:`pickle`
|
||||
protocol available.
|
||||
|
||||
* Added the :attr:`django.db.models.ForeignKey.db_constraint`
|
||||
option.
|
||||
* Added the :attr:`django.db.models.ForeignKey.db_constraint` and
|
||||
:attr:`django.db.models.ManyToManyField.db_constraint` options.
|
||||
|
||||
* The jQuery library embedded in the admin has been upgraded to version 1.9.1.
|
||||
|
||||
|
|
|
|||
|
|
@ -90,7 +90,10 @@ class Item(models.Model):
|
|||
|
||||
@python_2_unicode_compatible
|
||||
class Object(models.Model):
|
||||
pass
|
||||
related_objects = models.ManyToManyField("self", db_constraint=False, symmetrical=False)
|
||||
|
||||
def __str__(self):
|
||||
return str(self.id)
|
||||
|
||||
|
||||
@python_2_unicode_compatible
|
||||
|
|
|
|||
|
|
@ -12,13 +12,12 @@ from django.db import (backend, connection, connections, DEFAULT_DB_ALIAS,
|
|||
from django.db.backends.signals import connection_created
|
||||
from django.db.backends.postgresql_psycopg2 import version as pg_version
|
||||
from django.db.models import Sum, Avg, Variance, StdDev
|
||||
from django.db.utils import ConnectionHandler, DatabaseError
|
||||
from django.db.utils import ConnectionHandler
|
||||
from django.test import (TestCase, skipUnlessDBFeature, skipIfDBFeature,
|
||||
TransactionTestCase)
|
||||
from django.test.utils import override_settings, str_prefix
|
||||
from django.utils import six
|
||||
from django.utils import six, unittest
|
||||
from django.utils.six.moves import xrange
|
||||
from django.utils import unittest
|
||||
|
||||
from . import models
|
||||
|
||||
|
|
@ -52,7 +51,7 @@ class OracleChecks(unittest.TestCase):
|
|||
convert_unicode = backend.convert_unicode
|
||||
cursor = connection.cursor()
|
||||
cursor.callproc(convert_unicode('DBMS_SESSION.SET_IDENTIFIER'),
|
||||
[convert_unicode('_django_testing!'),])
|
||||
[convert_unicode('_django_testing!')])
|
||||
|
||||
@unittest.skipUnless(connection.vendor == 'oracle',
|
||||
"No need to check Oracle cursor semantics")
|
||||
|
|
@ -72,7 +71,7 @@ class OracleChecks(unittest.TestCase):
|
|||
c = connection.cursor()
|
||||
c.execute('CREATE TABLE ltext ("TEXT" NCLOB)')
|
||||
long_str = ''.join([six.text_type(x) for x in xrange(4000)])
|
||||
c.execute('INSERT INTO ltext VALUES (%s)',[long_str])
|
||||
c.execute('INSERT INTO ltext VALUES (%s)', [long_str])
|
||||
c.execute('SELECT text FROM ltext')
|
||||
row = c.fetchone()
|
||||
self.assertEqual(long_str, row[0].read())
|
||||
|
|
@ -99,6 +98,7 @@ class OracleChecks(unittest.TestCase):
|
|||
c.execute(query)
|
||||
self.assertEqual(c.fetchone()[0], 1)
|
||||
|
||||
|
||||
class MySQLTests(TestCase):
|
||||
@unittest.skipUnless(connection.vendor == 'mysql',
|
||||
"Test valid only for MySQL")
|
||||
|
|
@ -117,7 +117,7 @@ class MySQLTests(TestCase):
|
|||
found_reset = False
|
||||
for sql in statements:
|
||||
found_reset = found_reset or 'ALTER TABLE' in sql
|
||||
if connection.mysql_version < (5,0,13):
|
||||
if connection.mysql_version < (5, 0, 13):
|
||||
self.assertTrue(found_reset)
|
||||
else:
|
||||
self.assertFalse(found_reset)
|
||||
|
|
@ -182,6 +182,7 @@ class LastExecutedQueryTest(TestCase):
|
|||
self.assertEqual(connection.queries[-1]['sql'],
|
||||
str_prefix("QUERY = %(_)s\"SELECT strftime('%%Y', 'now');\" - PARAMS = ()"))
|
||||
|
||||
|
||||
class ParameterHandlingTest(TestCase):
|
||||
def test_bad_parameter_count(self):
|
||||
"An executemany call with too many/not enough parameters will raise an exception (Refs #12612)"
|
||||
|
|
@ -191,8 +192,9 @@ class ParameterHandlingTest(TestCase):
|
|||
connection.ops.quote_name('root'),
|
||||
connection.ops.quote_name('square')
|
||||
))
|
||||
self.assertRaises(Exception, cursor.executemany, query, [(1,2,3),])
|
||||
self.assertRaises(Exception, cursor.executemany, query, [(1,),])
|
||||
self.assertRaises(Exception, cursor.executemany, query, [(1, 2, 3)])
|
||||
self.assertRaises(Exception, cursor.executemany, query, [(1,)])
|
||||
|
||||
|
||||
# Unfortunately, the following tests would be a good test to run on all
|
||||
# backends, but it breaks MySQL hard. Until #13711 is fixed, it can't be run
|
||||
|
|
@ -240,6 +242,7 @@ class LongNameTest(TestCase):
|
|||
for statement in connection.ops.sql_flush(no_style(), tables, sequences):
|
||||
cursor.execute(statement)
|
||||
|
||||
|
||||
class SequenceResetTest(TestCase):
|
||||
def test_generic_relation(self):
|
||||
"Sequence names are correct when resetting generic relations (Ref #13941)"
|
||||
|
|
@ -257,6 +260,7 @@ class SequenceResetTest(TestCase):
|
|||
obj = models.Post.objects.create(name='New post', text='goodbye world')
|
||||
self.assertTrue(obj.pk > 10)
|
||||
|
||||
|
||||
class PostgresVersionTest(TestCase):
|
||||
def assert_parses(self, version_string, version):
|
||||
self.assertEqual(pg_version._parse_version(version_string), version)
|
||||
|
|
@ -291,6 +295,7 @@ class PostgresVersionTest(TestCase):
|
|||
conn = OlderConnectionMock()
|
||||
self.assertEqual(pg_version.get_version(conn), 80300)
|
||||
|
||||
|
||||
class PostgresNewConnectionTest(TestCase):
|
||||
"""
|
||||
#17062: PostgreSQL shouldn't roll back SET TIME ZONE, even if the first
|
||||
|
|
@ -338,17 +343,18 @@ class ConnectionCreatedSignalTest(TestCase):
|
|||
@skipUnlessDBFeature('test_db_allows_multiple_connections')
|
||||
def test_signal(self):
|
||||
data = {}
|
||||
|
||||
def receiver(sender, connection, **kwargs):
|
||||
data["connection"] = connection
|
||||
|
||||
connection_created.connect(receiver)
|
||||
connection.close()
|
||||
cursor = connection.cursor()
|
||||
connection.cursor()
|
||||
self.assertTrue(data["connection"].connection is connection.connection)
|
||||
|
||||
connection_created.disconnect(receiver)
|
||||
data.clear()
|
||||
cursor = connection.cursor()
|
||||
connection.cursor()
|
||||
self.assertTrue(data == {})
|
||||
|
||||
|
||||
|
|
@ -443,7 +449,7 @@ class BackendTestCase(TestCase):
|
|||
old_password = connection.settings_dict['PASSWORD']
|
||||
connection.settings_dict['PASSWORD'] = "françois"
|
||||
try:
|
||||
cursor = connection.cursor()
|
||||
connection.cursor()
|
||||
except DatabaseError:
|
||||
# As password is probably wrong, a database exception is expected
|
||||
pass
|
||||
|
|
@ -470,6 +476,7 @@ class BackendTestCase(TestCase):
|
|||
with self.assertRaises(DatabaseError):
|
||||
cursor.execute(query)
|
||||
|
||||
|
||||
# We don't make these tests conditional because that means we would need to
|
||||
# check and differentiate between:
|
||||
# * MySQL+InnoDB, MySQL+MYISAM (something we currently can't do).
|
||||
|
|
@ -477,7 +484,6 @@ class BackendTestCase(TestCase):
|
|||
# on or not, something that would be controlled by runtime support and user
|
||||
# preference.
|
||||
# verify if its type is django.database.db.IntegrityError.
|
||||
|
||||
class FkConstraintsTests(TransactionTestCase):
|
||||
|
||||
def setUp(self):
|
||||
|
|
@ -581,6 +587,7 @@ class ThreadTests(TestCase):
|
|||
connections_dict = {}
|
||||
connection.cursor()
|
||||
connections_dict[id(connection)] = connection
|
||||
|
||||
def runner():
|
||||
# Passing django.db.connection between threads doesn't work while
|
||||
# connections[DEFAULT_DB_ALIAS] does.
|
||||
|
|
@ -602,7 +609,7 @@ class ThreadTests(TestCase):
|
|||
# Finish by closing the connections opened by the other threads (the
|
||||
# connection opened in the main thread will automatically be closed on
|
||||
# teardown).
|
||||
for conn in connections_dict.values() :
|
||||
for conn in connections_dict.values():
|
||||
if conn is not connection:
|
||||
conn.close()
|
||||
|
||||
|
|
@ -616,6 +623,7 @@ class ThreadTests(TestCase):
|
|||
connections_dict = {}
|
||||
for conn in connections.all():
|
||||
connections_dict[id(conn)] = conn
|
||||
|
||||
def runner():
|
||||
from django.db import connections
|
||||
for conn in connections.all():
|
||||
|
|
@ -682,6 +690,7 @@ class ThreadTests(TestCase):
|
|||
"""
|
||||
# First, without explicitly enabling the connection for sharing.
|
||||
exceptions = set()
|
||||
|
||||
def runner1():
|
||||
def runner2(other_thread_connection):
|
||||
try:
|
||||
|
|
@ -699,6 +708,7 @@ class ThreadTests(TestCase):
|
|||
|
||||
# Then, with explicitly enabling the connection for sharing.
|
||||
exceptions = set()
|
||||
|
||||
def runner1():
|
||||
def runner2(other_thread_connection):
|
||||
try:
|
||||
|
|
@ -746,3 +756,14 @@ class DBConstraintTestCase(TransactionTestCase):
|
|||
|
||||
with self.assertRaises(models.Object.DoesNotExist):
|
||||
ref.obj
|
||||
|
||||
def test_many_to_many(self):
|
||||
obj = models.Object.objects.create()
|
||||
obj.related_objects.create()
|
||||
self.assertEqual(models.Object.objects.count(), 2)
|
||||
self.assertEqual(obj.related_objects.count(), 1)
|
||||
|
||||
intermediary_model = models.Object._meta.get_field_by_name("related_objects")[0].rel.through
|
||||
intermediary_model.objects.create(from_object_id=obj.id, to_object_id=12345)
|
||||
self.assertEqual(obj.related_objects.count(), 1)
|
||||
self.assertEqual(intermediary_model.objects.count(), 2)
|
||||
|
|
|
|||
Loading…
Reference in New Issue